The invention relates to a medical instrument and, more particularly, to medical scissors and/or graspers and the like, the manufacture of which is greatly simplified so as to render the instrument economic to manufacture whether disposable or reusable.
Hand operated medical scissors or graspers are commonly used during various open or laparascopic medical procedures. In order to facilitate such procedures, the tool may be mounted at one end of an elongated tube, with handle means at the other end of the tube, with a mechanical connection disposed therebetween, inside the tube, to operate the tool responsive to manipulation of the handle means.
The instrument and, particularly, the mechanical connection must be sturdy and reliable so as to preclude breakage of the instrument during use and the potentially severe medical consequences stemming therefrom.
Further, the necessity in the medical field for sterility and sharpness makes it desirable for such instruments, or at least the tips or operative portions of such instruments, to be disposable and, therefore, simple and inexpensive in manufacture.
One known approach to the mechanical link is to dispose a push-pull rod, or actuating rod, movably inside the elongated tube. The rod is connected to handle means at one connection between the tool elements and the rod of such known devices is made through straight linkage elements which are connected to the tool elements. The tool elements have laterally offset linkage ends for connection with the straight links. It is costly, however, to manufacture tool elements such as scissor blades or grasper arms, with such a laterally offset section. Thus, such instruments are not sufficiently inexpensive in manufacture and, therefore, may not be readily disposable or economically replaceable.
U.S. Pat. No. 5,147,357 to Rose et. al. is an example of a device having a mechanical connection which uses spherical gears and gear rods to impart the desired motion from a handle structure through an actuating rod to the scissors structure. The spherical gears and gear rods used in Rose et. al. render the instrument expensive in manufacture.
It is preferable, however, as set forth above, for such instruments or the tool elements to be disposable so as to allow the instrument or parts thereof to be discarded after use, thereby avoiding the necessity for sharpening and sterilizing instruments designed for multiple uses.
It is therefore the principal object of the present invention to provide a medical instrument such as medical scissors or graspers which is both reliable and inexpensive in manufacture.
It is a further object of the present invention to provide such an instrument which is small in cross section so as to allow use with an incision of minimal size or through a small sized cannula for laparascopic procedures.
It is still another object of the present invention to provide such an instrument having means for cauterizing the wound formed by the instrument.
Other objects and advantages will appear hereinbelow.